This invention relates to sintered polycrystalline diamond, specifically sintered polycrystalline diamond that is formed in a high temperature high pressure press. The prior art discloses sintered polycrystalline diamond that utilizes metal catalysts to promote diamond growth.
U.S. Pat. No. 6,562,462 to Griffin et al., which is herein incorporated by reference for all that it contains, discloses a polycrystalline diamond or a diamond-like element with greatly improved wear resistance without loss of impact strength. These elements are formed with a binder-catalyzing material in a high-temperature, high-pressure (HTHP) process. The PCD element has a body with a plurality of bonded diamond or diamond-like crystals forming a continuous diamond matrix that has a diamond volume density greater than 85%. Interstices among the diamond crystals form a continuous interstitial matrix containing a catalyzing material. The diamond matrix table is formed and integrally bonded with a metallic substrate containing the catalyzing material during the HTHP process. The diamond matrix body has a working surface, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material, and the remaining interstitial matrix contains the catalyzing material. Typically, less than about 70% of the body of the diamond matrix table is free of catalyzing material.
U.S. Pat. No. 4,518,659 to Gigl et al., which is herein incorporated by reference for all that it contains, discloses a method for the high pressure/high temperature catalyst sweep through process for making diamond and cubic boron nitride compacts has been improved by adding and intermediate alloy. The added metal (whether alone or contained in an alloy) has a melting point below that of the catalyst (e.g. cobalt), is miscible with the catalyst, and preferably sweeps through the mass of abrasive crystals first.